Compressor

ABSTRACT

A compressor includes a suction chamber and a discharge chamber in the housing. A first component is secured to a second component to form the housing. A first defining wall and a second defining wall are located in the second component to define the suction chamber and the discharge chamber. The second defining wall is located radially inward of the first defining wall. An inner fastener is located radially inward of the first defining wall and secures the first component to the second component.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a compressor used in a vehicle air conditioner. More particularly, the present invention pertains to a coupling structure of a compressor housing.

[0002]FIG. 11 shows a typical piston type compressor. The compressor includes a housing 101, which consists of a front housing member 102, a cylinder block 103, and a rear housing member 104. The front housing member 102, the cylinder block 103, and the rear housing member 104 are secured together with through bolts 105.

[0003] The cylinder block 103 and the rear housing member 104 are secured to each other with a valve plate assembly 106 held in between. A discharge chamber 107 is defined at the peripheral portion of the rear housing member 104 and a suction chamber 108 is defined radially inward of the discharge chamber 107. The rear housing member 104 includes an annular first defining wall 109 and an annular second defining wall 110. The first defining wall 109 surrounds the discharge chamber 107. The second defining wall 110 defines the discharge chamber 107 and the suction chamber 108 radially inward of the first defining wall 109.

[0004] The through bolts 105 extend through the outermost portion of the housing 101. Particularly, the through bolts 105 are threaded into the first defining wall 109 so that the rear housing member 104 is secured to the cylinder block 103.

[0005] The second defining wall 110 is located radially inward of the first defining wall 109 inside the rear housing member 104. When the first defining wall 109 is fastened to the cylinder block 103 with the through bolts 105, the fastening force is transmitted to the second defining wall 110 by the rigidity (non-flexibility) of the rear housing member 104, which presses the second defining wall 110 against the cylinder block 103 with the valve plate assembly 106 in between.

[0006] To reliably hold the valve plate assembly 106 between the second defining wall 110 and the cylinder block 103 and to reliably separate the discharge chamber 107 from the suction chamber 108, the rear housing member 104 needs to have high rigidity. However, the weight of the rear housing member 104 is increased when the rigidity of the rear housing member 104 is increased.

SUMMARY OF THE INVENTION

[0007] Accordingly, it is an objective of the present invention to provide a compressor that has a coupling structure of a housing that permits the housing to maintain the rigidity without increasing the weight.

[0008] To achieve the above objective, the present invention provides a compressor having a suction chamber and a discharge chamber in a housing. The compressor includes a first component, a second component, and an inner fastener. The second component is secured to the first component. The first and second components form the housing. The second component includes a first defining wall and a second defining wall for defining the suction chamber and the discharge chamber inside the second component. The second defining wall is located radially inward of the first defining wall. The inner fastener is located radially inward of the first defining wall. The inner fastener secures the first component to the second component.

[0009] Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:

[0011]FIG. 1 is a cross-sectional view illustrating a single-headed piston type variable displacement compressor according to a first embodiment of the present invention;

[0012]FIG. 2 is a cross-sectional view taken along line 2-2 shown in FIG. 1;

[0013]FIG. 3 is an enlarged partial cross-sectional view illustrating a compressor according to a second embodiment of the present invention;

[0014]FIG. 4 is an enlarged partial cross-sectional view illustrating a compressor according to a third embodiment of the present invention;

[0015]FIG. 5 is an enlarged partial cross-sectional view illustrating a compressor according to a fourth embodiment of the present invention;

[0016]FIG. 6 is an enlarged partial cross-sectional view illustrating a compressor according to a fifth embodiment of the present invention;

[0017]FIG. 7 is an enlarged partial cross-sectional view illustrating a compressor according to a sixth embodiment of the present invention;

[0018]FIG. 8 is an enlarged partial cross-sectional view illustrating a compressor according to a seventh embodiment of the present invention;

[0019]FIG. 9 is an enlarged partial cross-sectional view illustrating a compressor according to an eighth embodiment of the present invention;

[0020]FIG. 10(a) is a cross-sectional view illustrating a double-headed piston type fixed displacement compressor according to a ninth embodiment of the present invention;

[0021]FIG. 10(b) is an enlarged partial cross-sectional view of the compressor shown in FIG. 10(a); and

[0022]FIG. 11 is a cross-sectional view illustrating a prior art single-headed piston type variable displacement compressor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Compressors according to first to ninth embodiments of the present invention will be described. The compressors are used in vehicle air conditioners. The differences from the first embodiment will mainly be discussed for the second to ninth embodiments and like members are given the like numbers and detailed explanations are omitted.

[0024] As shown in FIG. 1, a single-headed piston type variable displacement compressor (hereinafter, simply referred to as a compressor) has a housing 11, which includes a cylinder block 12, a front housing member 13, and a rear housing member 15. The front housing member 13 is secured to the front end (left end as viewed in FIG. 1) of the cylinder block 12. The rear housing member 15 is secured to the rear end (right end as viewed in FIG. 1) of the cylinder block 12. A valve plate assembly 14 is located between the cylinder block 12 and the rear housing member 15. The cylinder block 12, the front housing member 13, and the rear housing member 15 are made of aluminum-based metal. The valve plate assembly 14 includes multiple plates stacked together.

[0025] The cylinder block 12 and the front housing member 13 define a crank chamber 16. A drive shaft 17 is rotatably supported in the crank chamber 16. The drive shaft 17 is coupled to and driven by an engine (not shown) of a vehicle.

[0026] A lug plate 18 is located in the crank chamber 16 and is secured to the drive shaft 17 to rotate integrally with the drive shaft 17. A cam plate, which is a swash plate 19 in the first embodiment, is located in the crank chamber 16. The swash plate 19 slides along the drive shaft 17 and inclines with respect to the axis of the drive shaft 17. A hinge mechanism 20 is provided between the lug plate 18 and the swash plate 19. The hinge mechanism 20 causes the swash plate 19 to rotate integrally with the lug plate 18 and the drive shaft 17. The hinge mechanism 20 also causes the swash plate 19 to slide along the axial direction of the drive shaft 17 and to incline with respect to the drive shaft 17.

[0027] Cylinder bores 12 a (only one shown) are formed in the cylinder block 12 to surround the drive shaft 17. A single headed piston 21 is reciprocally accommodated in each cylinder bore 12 a. The front opening of each cylinder bore 12 a is closed with the corresponding piston 21 and the rear opening of each cylinder bore 12 a is closed with the valve plate assembly 14. A compression chamber 22 is defined in each cylinder bore 12 a. The volume of each compression chamber 22 changes in accordance with the reciprocation of the corresponding piston 21. Each piston 21 is coupled to the peripheral portion of the swash plate 19 by a pair of shoes 23. Therefore, when the swash plate 19 rotates with the drive shaft 17, the shoes 23 convert the rotation of the swash plate 19 into reciprocation of the pistons 21.

[0028] A suction chamber 24 and a discharge chamber 25 are defined between the valve plate assembly 14 and the rear housing member 15. The valve plate assembly 14 has suction ports 26, suction valve flaps 27, discharge ports 28 and discharge valve flaps 29. Each set of the suction port 26, the suction valve flap 27, the discharge port 28 and the discharge valve flap 29 corresponds to one of the cylinder bores 12 a. When each piston 21 moves from the top dead center position to the bottom dead center position, refrigerant gas in the suction chamber 24 is drawn into the corresponding compression chamber 22 via the corresponding suction port 26 and suction valve flap 27. When each piston 21 moves from the bottom dead center position to the top dead center position, refrigerant gas in the corresponding compression chamber 22 is compressed to a predetermined pressure and is discharged to the discharge chamber 25 via the corresponding discharge port 28 and discharge valve flap 29.

[0029] The compressor has a known control valve (not shown). The degree of opening of the control valve is changed for controlling the pressure is the crank chamber 16. In accordance with a change in the pressure in the crank chamber 16, the difference between the pressure in the crank chamber 16 and the pressure in each compression chamber 22 is changed, which alters the inclination angle of the swash plate 19. As a result, the stroke of each piston 21, that is, the discharge displacement of the compressor, is controlled.

[0030] As shown in FIGS. 1 and 2, a plurality of components (the cylinder block 12, the front housing member 13, and the rear housing member 15 in the first embodiment) are secured to each other to form the housing 11. The cylinder block 12, which is a first component, is secured to the rear housing member 15, which is a second component serving as an end housing at the rear side, so that the discharge chamber 25 is formed at the peripheral annular portion of the rear housing member 15 and the suction chamber 24 is defined radially inward of the discharge chamber 25.

[0031] The rear housing member 15 includes an annular first defining wall 31, which surrounds the discharge chamber 25, and an annular second defining wall 32, which separates the discharge chamber 25 from the suction chamber 24 inside the first defining wall 31. The distal end 31 a of the first defining wall 31 is pressed against the rear surface of the cylinder block 12 via the valve plate assembly 14. This shuts out the atmospheric air from the discharge chamber 25. The distal end 32 a of the second defining wall 32 is pressed against the rear surface of the cylinder block 12 via the valve plate assembly 14. This separates the discharge chamber 25 from the suction chamber 24.

[0032] An outer fastener and an inner fastener are used to secure the rear housing member 15 to the cylinder block 12. Therefore, the first defining wall 31 and the second defining wall 32 are pressed against the cylinder block 12 in a suitable manner, or the cylinder block 12 and the rear housing member 15 hold the valve plate assembly 14 in a suitable manner.

[0033] The outer fastener includes outer through bolts 41 (six outer through bolts in the first embodiment) and outer threaded holes 31 b. The outer through bolts 41 are located at the outermost portion of the housing 11 at substantially equal angular intervals about the drive shaft 17. Each outer through bolt 41 is inserted from the front housing member 13 extending through the cylinder block 12 and the valve plate assembly 14. Each outer through bolt 41 then reaches the rear housing member 15. The outer threaded holes 31 b are formed in the distal end 31 a of the first defining wall 31 of the rear housing member 15. The distal end of each outer through bolt 41 is threaded into the corresponding outer threaded hole 31 b. Therefore, the rear housing member 15 is secured to the cylinder block 12 at the portion where the distal ends of the outer through bolts 41 are threaded into the first defining wall 31.

[0034] The inner fastener of the first embodiment secures the rear housing member 15 to the cylinder block 12 at a portion inward of the first defining wall 31, or inward of the outer fastener (such as the outer through bolts 41 and the outer threaded holes 31 b).

[0035] The inner fastener includes an inner through bolt 42 and an inner threaded hole 12 b, which are located at the center of the housing 11. The inner through bolt 42 is inserted from the rear housing member 15 extending through the suction chamber 24 and the valve plate assembly 14. The inner through bolt 42 then reaches the cylinder block 12. The distal end of the inner through bolt 42 is threaded into the inner threaded hole 12 b, which is formed at the center of the rear end of the cylinder block 12. Therefore, the rear housing member 15 is secured to the cylinder block 12 at the portion radially inward of the second defining wall 32 where the inner fastener (the inner through bolt 42 and the inner threaded hole 12 b) is threaded into the cylinder block 12.

[0036] The first embodiment provides the following advantages.

[0037] (1) The cylinder block 12 and the rear housing member 15 are secured to each other by the inner fastener (such as the inner through bolt 42) at the portion radially inward of the outer fastener (such as the outer through bolts 41). Therefore, a portion of the rear housing member 15 radially inward of the first defining wall 31 is reliably prevented from being deformed. This permits the second defining wall 32 to be reliably pressed against the cylinder block 12 without depending on the tightening force of the outer fastener and the rigidity of the rear housing member 15. Thus, the rear housing member 15 may have less rigidity, which permits the weight of the rear housing member 15 to be reduced. This in turn permits the weight of the compressor to be reduced.

[0038] (2) The outer fastener secures the cylinder block 12 to the rear housing member 15 at a portion radially outward of the second defining wall 32. The inner fastener secures the cylinder block 12 to the rear housing member 15 at the portion radially inward of the second defining wall 32. That is, the cylinder block 12 is secured to the rear housing member 15 at both portions radially inward and outward of the second defining wall 32. Thus, the deformation of the portion of the rear housing member 15 radially inward of the first defining wall 31 is reliably suppressed. Therefore, the second defining wall 32 is reliably pressed against the cylinder block 12. Accordingly, the above described advantage (1) is more effectively provided.

[0039] (3) The inner through bolt 42 is used as the inner fastener. Therefore, compared with a case when a press fitting pin is used as the inner fastener (as will be described in a fourth embodiment), each part (the thread of the inner through bolt 42 and the inner threaded hole 12 b) needs not be manufactured as accurately as in the case when the press fitting pin is used to reliably secure the second defining wall 32 to the cylinder block 12. In the case, when the press fitting pin is used, each part needs to be manufactured with high accuracy to obtain a predetermined contact area. Also, the inner through bolt 42 can easily be tightened again when the second defining wall 32 and the cylinder block 12 become loose. This facilitates the maintenance procedure of the compressor.

[0040] (4) The inner through bolt 42, which is the inner fastener, is inserted through the center of the suction chamber 24. Therefore, the inner through bolt 42 causes the refrigerant gas in the suction chamber 24 to flow about the inner through bolt 42. This increases the suction efficiency of the compressor.

[0041]FIG. 3 shows a second embodiment. According to the second embodiment, the inner through bolt 42, which is the inner fastener, is inserted from the rear housing member 15. The inner through bolt extends through the second defining wall 32 and the valve plate assembly 14 and then threaded into the inner threaded hole 12 b of the cylinder block 12. That is, the cylinder block 12 is directly secured to the rear housing member 15 at the second defining wall 32. Therefore, the advantage (1) of the first embodiment is more effectively provided.

[0042] A bore through which the inner through bolt 42 is inserted is separated from the suction chamber 24 and the discharge chamber 25 since the second defining wall 32 is pressed against the valve plate assembly 14 by tightening the inner through bolt 42. Therefore, the atmospheric air is reliably shut out from the suction chamber 24 and the discharge chamber 25.

[0043] The inner fastener (such as the inner through bolt 42 and the inner threaded hole 12 b) may be located at only one place. The inner fastener may also be located at six places as a modified embodiment 1 (ME1) shown in FIG. 2. The number of the inner fastener is not limited to that of the modified embodiment 1 shown in FIG. 2 (six places) but may also be two, three, four, five, or seven.

[0044]FIG. 4 shows a third embodiment. According to the third embodiment, the inner through bolt 42, which is the inner fastener, is inserted from the rear housing member 15. The inner through bolt 42 extends through the discharge chamber 25 and the valve plate assembly 14 and is threaded into the inner threaded hole 12 b of the cylinder block 12. Therefore, the cylinder block 12 and the rear housing member 15 are secured by the inner fastener (the inner through bolt 42 and the inner threaded hole 12 b) located radially inward of the first defining wall 31 and radially outward of the second defining wall 32. The third embodiment also provides the advantage (1) of the first embodiment.

[0045] The inner fastener (the inner through bolt 42 and the inner threaded hole 12 b) may be located at only one place. The inner fastener may also be located at a number of places as shown in a modified embodiment 2 (ME2) shown in FIG. 2. The number of the inner fastener is not limited to that of the modified embodiment shown in FIG. 2 (six places) but may also be two, three, four, five, or seven.

[0046]FIG. 5 shows a fourth embodiment. The inner fastener according to the fourth embodiment includes a press fitting pin 45. The press fitting pin 45 is inserted through the valve plate assembly 14. The rear end (right end as viewed in FIG. 5) of the press fitting pin 45 is press fitted into a press fitting bore 32 b formed in the distal end 32 a of the second defining wall 32. The front end (left end as viewed in FIG. 5) of the press fitting pin 45 is press fitted into a press fitting bore 12 c formed in the rear end of the cylinder block 12. The press fitting pin 45 directly secures the cylinder block 12 to the rear housing member 15 at the second defining wall 32.

[0047] The fourth embodiment provides the same advantages as the first embodiment. Since the press fitting pin 45 is used as the inner fastener, the second defining wall 32 of the rear housing member 15 and the cylinder block 12 are secured to each other by a simple operation of press fitting one to the other. Also, a fastener such as the press fitting pin 45 is smaller than the through bolts. This facilitates the inner fastener (such as the press fitting pin 45 and the press fitting bores 12 c, 32 b) to be inserted through the second defining wall 32.

[0048] The inner fastener (the press fitting pin 45 and the press fitting bores 12 c, 32 b) may be located at only one place. The inner fastener may also be located at a number of places as shown in the modified embodiment 1 (ME1) as shown in FIG. 2. The number of the inner fastener is not limited to that of the modified embodiment shown in FIG. 2 (six places) but may also be two, three, four, five, or seven.

[0049]FIG. 6 shows a fifth embodiment. A cylindrical coupler 46 is integrally formed on the distal end 32 a of the second defining wall 32. The coupler 46 is inserted through the valve plate assembly 14 and is press fitted into the press fitting bore 12 c of the cylinder block 12. Thus, the coupler 46 directly secures the cylinder block 12 to the rear housing member 15 at the second defining wall 32.

[0050] The fifth embodiment also provides the same advantages as the fourth embodiment. In addition, the coupler 46 is integrally formed with the second defining wall 32 (the rear housing member 15). This prevents the number of parts of the compressor from being increased.

[0051] The inner fastener (such as the coupler 46 and the press fitting bores 12 c) may be located at only one place. The inner fastener may also be located at a number of places as shown in the modified embodiment 1 of FIG. 2. The number of the inner fastener is not limited to that of the modified embodiment shown in FIG. 2 (six places) but may also be 2, 3, 4, 5, or 7.

[0052]FIG. 7 shows a sixth embodiment. The sixth embodiment differs in that the coupler 46 is integrally formed with the cylinder block 12 instead of the rear housing member 15. The sixth embodiment also provides the same advantages as the fifth embodiment.

[0053]FIG. 8 shows a seventh embodiment. According to the seventh embodiment, the cylindrical coupler 46 is integrally formed on the inner wall of the discharge chamber 25 in the rear housing member 15. The coupler 46 is inserted through the valve plate assembly 14. The distal end of the coupler 46 is press fitted into the press fitting bore 12 c of the cylinder block 12. That is, the cylinder block 12 is secured to the rear housing member 15 with the inner fastener (the coupler 46 and the press fitting bore 12 c) located radially inward of the first defining wall 31 and radially outward of the second defining wall 32. The seventh embodiment provides the same advantages as the fifth embodiment.

[0054] The inner fastener (the coupler 46 and the press fitting bore 12 c) may be located at only one place. The inner fastener may also be located at a number of places as shown in the modified embodiment 2 of FIG. 2. The number of the inner fastener is not limited to that of the modified embodiment shown in FIG. 2 (six places) but may also be two, three, four, five, or seven.

[0055]FIG. 9 shows an eighth embodiment. According to the eighth embodiment, the cylindrical coupler 46 is integrally formed on the inner wall of the suction chamber 24 in the rear housing member 15. The coupler 46 is inserted through the valve plate assembly 14. The distal end of the coupler 46 is press fitted into the press fitting bore 12 c. That is, the cylinder block 12 is secured to the rear housing member 15 with the inner fastener (the coupler 46 and the press fitting bore 12 c) located radially inward of the second defining wall 32. The eighth embodiment provides the same advantages as the fifth embodiment.

[0056] The inner fastener (the coupler 46 and the press fitting bore 12 c) may be located at only one place. The inner fastener may also be located at a number of places as shown in a modified embodiment 3 of FIG. 2. The number of the inner fastener is not limited to that of the modified embodiment shown in FIG. 2 (six places) but may also be two, three, four, five, or seven.

[0057]FIG. 10(a) and 10(b) shows a ninth embodiment. The ninth embodiment relates to a double-headed piston type compressor (hereinafter, simply referred to as a compressor), which includes a double-headed piston 21. More specifically, the ninth embodiment pertains to a coupling structure of the housing 11. The compressor is a fixed displacement type compressor in which the swash plate 19 is fixed such that the swash plate 19 does not incline with respect to the drive shaft 17. The lug plate 18 and the hinge mechanism 20 are omitted.

[0058] The housing 11 of the compressor includes a front cylinder block 12A and a rear cylinder block 12B each having cylinder bores 12 a. The front cylinder block 12A is secured to the rear cylinder block 12B. The housing 11 also includes a front housing member 13 and a rear housing member 15. The front housing member 13 is secured to the front end (left end as viewed in FIG. 10(a)) of the front cylinder block 12A with a valve plate assembly 14 arranged in between. The rear housing member 15 is secured to the rear end (right end as viewed in FIG. 10(a)) of the rear cylinder block 12B with another valve plate assembly 14 arranged in between.

[0059] The front cylinder block 12A forms a first component and the front housing member 13, which is a front side end housing, forms a second component. The front cylinder block 12A is secured to the front housing member 13 so that an annular suction chamber 24 is defined at the peripheral portion of the front housing member 13 and a discharge chamber 25 is defined radially inward of the suction chamber 24.

[0060] The rear cylinder block 12B also forms a first component and the rear housing member 15 also forms a second component. The rear cylinder block 12B is secured to the rear housing member 15 so that another annular suction chamber 24 is defined at the peripheral portion of the rear housing member 15 and another discharge chamber 25 is defined radially inward of the suction chamber 24.

[0061] The front housing member 13 and the rear housing member 15 each includes an annular first defining wall 31, which surrounds the corresponding suction chamber 24, and an annular second defining wall 32, which separates the suction chamber 24 from the corresponding discharge chamber 25 inside the first defining wall 31.

[0062] The press fitting pin 45 shown in the fourth embodiment is used as the inner fastener to secure the front housing member 13 to the front cylinder block 12A. The inner through bolt 42 shown in the first embodiment is used as the inner fastener to secure the rear housing member 15 to the rear cylinder block 12B. The ninth embodiment provides the advantage (1) of the first embodiment for both the front housing member 13 and the rear housing member 15.

[0063] It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the invention may be embodied in the following forms.

[0064] As shown in a modified embodiment 4 of FIG. 2, the inner fastener of the first embodiment may be increased to a number of inner fasteners (such as the through bolts 42 and inner threaded holes 12 b). The number of the inner fasteners is not limited to that of the modified embodiment shown in FIG. 2 (two places) but may also be three, four, or five.

[0065] At least two or more of the arrangement of the inner fastener described in the first to eighth embodiments may be used together.

[0066] The outer fastener may be changed to a press fitting structure such as that similar to the inner fastener described in the fourth to eighth embodiments. In the case when the invention according to fourth to eighth embodiments are provided with such outer fastener, the cylinder block 12, the front housing member 13, and the rear housing member 15 are secured to each other by press fitting only. This significantly simplifies the assembling procedure of the housing 11.

[0067] The rear housing member 15 may be made of resin or magnesium-based metal. The prior art rear housing member 15 was limited to aluminum-based metal or iron-based metal. However, the rigidity of the rear housing member 15 can be reduced by applying the present invention. This increases flexibility in selecting the material.

[0068] The present invention is not limited to a piston type compressor but may also be applied to a rotary compressor such as a scroll compressor.

[0069] Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims. 

1. A compressor having a suction chamber and a discharge chamber in a housing, the compressor comprising: a first component; a second component, which is secured to the first component, wherein said first and second components form the housing, wherein the second component includes a first defining wall and a second defining wall for defining the suction chamber and the discharge chamber inside the second component, and wherein the second defining wall is located radially inward of the first defining wall; and an inner fastener located radially inward of the first defining wall, wherein the inner fastener secures the first component to the second component.
 2. The compressor according to claim 1, wherein the inner fastener is located radially inward of the second defining wall.
 3. The compressor according to claim 1, wherein the inner fastener is located on the second defining wall.
 4. The compressor according to claim 1, wherein the inner fastener is located radially inward of the first defining wall and radially outward of the second defining wall.
 5. The compressor according to claim 1, wherein the inner fastener includes a bolt.
 6. The compressor according to claim 1, wherein the inner fastener is a coupler, which extends from one of the first and second components and is press fitted to the other one of the first and second components.
 7. The compressor according to claim 6, wherein the inner fastener includes a cylindrical pin.
 8. The compressor according to claim 6, wherein the inner fastener is integrally formed with one of the first and second components.
 9. The compressor according to claim 1, further comprising an outer fastener for securing the first component to the second component at the first defining wall.
 10. The compressor according to claim 9, wherein the outer fastener is a plurality of bolts.
 11. The compressor according to claim 1, wherein the compressor is a piston type compressor, and the first component is a cylinder block in which cylinder bores are formed, wherein each cylinder bore accommodates a piston, and the second component is located at one end of the housing, and wherein a valve plate assembly is located between the first and second components.
 12. The compressor according to claim 5, wherein the suction chamber is located radially inward of the second defining wall, and wherein the discharge chamber is located between the first defining wall and the second defining wall.
 13. The compressor according to claim 12, wherein the inner fastener is inserted through the center of the suction chamber.
 14. The compressor according to claim 1, wherein the second component is made of resin or magnesium-based metal.
 15. A compressor comprising: a cylinder block, wherein the cylinder block has a cylinder bore; a piston movably accommodated in the cylinder bore; a rear housing member, which is secured to the cylinder block, wherein the rear housing member includes a first defining wall and a second defining wall, which define a discharge chamber in between said first and second defining walls, and wherein a suction chamber is defined radially inward of the second defining wall; a valve plate assembly located between the cylinder block and the rear housing member, wherein the valve plate assembly has a valve, which selectively communicates the suction chamber and the discharge chamber with the cylinder bore; and an inner fastener, which is inserted through one of the suction chamber and the discharge chamber, wherein the inner fastener secures the rear housing member to the cylinder block.
 16. The compressor according to claim 15, further comprising a plurality of outer fasteners for securing the cylinder block to the rear housing member at the first defining wall.
 17. The compressor according to claim 15, wherein the inner fastener includes a bolt.
 18. The compressor according to claim 15, wherein the inner fastener is a coupler, which extends from the rear housing member and is press fitted into the cylinder block.
 19. The compressor according to claim 18, wherein the inner fastener is integrally formed with the rear housing member. 